Copolymers of ethylene and selected acrylate esters

ABSTRACT

In the copolymerization of ethylene and acrylate esters, the use of selected acrylate esters suppresses the formation of acrylate ester homopolymer, and/or allows the rapid analysis by  1 H-NMR of the amount of homopolymer byproduct present in the copolymer, both aids in manufacturing high quality copolymers. Useful such acrylates include hexyl acrylate, 3,5,5-trimethylhexyl acrylate, 2-phenoxyethyl acrylate and 2-phenylethyl acrylate. The polymers are useful for films and molding resins.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 U.S.C. §119 from U.S.Provisional Application Ser. Nos. 60/208,087 (filed May 31, 2000),60/211,601 (filed Jun. 15, 2000), 60/214,036 (filed Jun. 23, 2000) and60/264,537 (filed Jan. 25, 2001), all of which are incorporated byreference herein as if fully set forth.

FIELD OF THE INVENTION

[0002] Copolymers of ethylene and selected acrylate esters may bereadily analyzed for the presence of acrylate ester homo-polymers,thereby rendering quality control during their manufacture cheaper andfaster. A process for copolymer manufacture is also disclosed. Thecopolymers are useful for films and as molding resins.

TECHNICAL BACKGROUND

[0003] Recently it has become possible to prepare copolymers of olefins,especially ethylene, with acrylate esters, using late transition metalpolymerization catalysts. See for instance U.S. Pat. No. 5,866,663, andS. D. Ittel, et al., Chem. Rev., vol. 100, p. 1169-1203 (2000), both ofwhich are incorporated by reference herein for all purposes as if fullyset forth.

[0004] One problem that sometimes occurs in these polymerizations is theformation of the desired copolymer together with some amount of ahomopolymer of the acrylate ester(s) (more than one ester may bepresent). This is believed to arise because acrylate esters also undergofacile free radical polymerizations, which can occur in the same systemas the transition metal catalyzed copolymerization with ethylene. Whileanalysis of the amount of homopolymer present and also the amount ofester group present in the copolymer can be done by ¹³C—NMRspectroscopy, such analyses are usually very time consuming, resultingin long delays between sampling and results, meaning adjustments to themanufacturing system to minimize homopolymer formation or adjust thelevel of acrylate incorporation may be delayed a long time, an obviousdisadvantage. This together with the high cost of the analysis itself isa drawback for making these copolymers by coordination polymerization.

[0005] Therefore homo- and copolymer mixtures that are readily analyzed,or the use of acrylate esters which do not homopolymerize readily undercoordination polymerization conditions, are desirable.

SUMMARY OF THE INVENTION

[0006] This invention concerns a process for the manufacture of acopolymer, comprising the step of contacting, under polymerizationconditions, a monomer component comprising ethylene and one or moreacrylate esters (and optionally one or more other polymerizableolefins), and a polymerization catalyst system containing a transitionmetal, wherein said one or more acrylate esters comprises a compound ofthe formula H₂C=CHC(O)OR¹, wherein:

[0007] R¹ is —CH₂CH₂X, an n-alkyl containing 6 or more carbon atoms, or—CH₂R²;

[0008] X is aryl, substituted aryl, hydrocarbyloxy, substitutedhydrocarbyloxy, fluoro or fluoroalkyl; and

[0009] R² is an alkyl containing at least one quaternary carbon atom, orhaving a grouping within R² having an E_(s) of about −1.0 or less, orboth.

[0010] This invention also concerns a copolymer of ethylene, one or moreacrylate esters of the formula H₂C=CHC(O)OR¹ (and optionally one or moreother copolymerizable monomers), provided that said acrylate esters areabout 0.1 to about 30 mole percent of the total number of all repeatunits in said copolymer, wherein:

[0011] R¹ is —(CH₂CH₂)X, n-alkyl containing 6 or more carbon atoms, or—CH₂R²;

[0012] X is aryl, substituted aryl, hydrocarbyloxy, substitutedhydrocarbyloxy, fluoro, or fluoroalkyl; and

[0013] R² is alkyl containing at least one quaternary carbon atom, orhaving a grouping within R² having an E_(s) of about −1.0 or less, orboth.

[0014] These and other features and advantages of the present inventionwill be more readily understood by those of ordinary skill in the artfrom a reading of the following detailed description. It is to beappreciated that certain features of the invention which are, forclarity, described below in the context of separate embodiments, mayalso be provided in combination in a single embodiment. Conversely,various features of the invention which are, for brevity, described inthe context of a single embodiment, may also be provided separately orin any subcombination.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 shows the ¹H-NMR spectrum of a mixture of an EGPEAhomopolymer in a mixture with an EGPEA compolymer with ethylene,produced as described in Example 1 while making the copolymer with anickel containing olefin polymerization catalyst. The assignments ofsome of the various peaks are shown.

[0016]FIG. 2 shows a typical ¹H-NMR of the polymer product fromcopolymerization of ethylene and methyl acrylate using a nickelcontaining polymerization catalyst. There is both copolymer andhomopolymer present. The homopolymer peak partially lies under acopolymer peak, and the black shaded portion is an illustration(probably not accurate) showing the actual size of the homopolymer peak.

[0017]FIG. 3 shows a typical ¹H-NMR of the polymer product fromcopolymerization of ethylene and n-hexyl acrylate using a nickelcontaining polymerization catalyst. There is both copolymer andhomopolymer present. The homopolymer peak partially lies under acopolymer peak, but it is easier to estimate the amount of homopolymerpresent than in the methyl acrylate case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Herein certain terms are used:

[0019] By a “quaternary carbon atom” is meant a carbon atom which isbound to 4 other carbon atoms. An example of a quaternary carbon atom isfound in the neopentyl group, —CH₂ C(CH₃)₃.

[0020] By “aryl” is meant a monovalent group in which the free valenceis to a carbon atom of an aromatic ring. The aromatic ring may be acarbocyclic ring or a heterocyclic ring. The aryl group may have one ormore aromatic rings, which may be fused, connected by single bonds orother groups.

[0021] A “hydrocarbyl group” is a univalent group containing only carbonand hydrogen. As examples of hydrocarbyls may be mentioned unsubstitutedalkyls, cycloalkyls and aryls. If not otherwise stated, it is preferredthat hydrocarbyl groups (and alkyl groups) herein contain 1 to about 30carbon atoms.

[0022] By a “fluoroalkyl” group is meant an alkyl group substituted withone or more fluorine atoms (and may be perfluoroalkyl). Preferably thereis at least one fluorine atom alpha or beta, more preferably alpha, tothe free valence of the alkyl group.

[0023] By “substituted” herein is meant a group which contains one ormore substituent groups which are inert under the process conditions towhich the compound containing these groups is subjected. The substituentgroups also do not substantially interfere with the process. Included inthe meaning of “substituted” are heteroaromatic rings. In substitutedgroups all of the hydrogens (which may be present) may be substituted,as in trifluoromethyl.

[0024] By “(inert) functional group” herein is meant a group which isinert under the process conditions to which the compound containing thegroup is subjected. That is, the functional groups do not substantiallyinterfere with any process described herein that the compound in whichthey are present may take part in. Examples of functional groups includehalo (fluoro, chloro, bromo and iodo), ether such as —OR²², thioethersuch as —SR²² and amine such as —NR₂ ²² wherein each R²² isindependently hydrocarbyl or substituted hydro-carbyl. In cases in whichthe functional group may be near a transition metal atom the functionalgroup should not coordinate to the metal atom more strongly than thegroups in those compounds are shown as coordinating to the metal atom,that is they should not displace the desired coordinating group.

[0025] By “under polymerization conditions” is meant the conditions fora polymerization that are usually used for the particular polymerizationcatalyst system being used. These conditions include parameters such aspressure, temperature, catalyst and cocatalyst (if present)concentrations, the type of process such as batch, semibatch,continuous, gas phase, solution or liquid slurry etc. Conditionsnormally done or used with the particular polymerization catalystsystem, such as the use of hydrogen for polymer molecular weightcontrol, are also considered “under polymerization conditions”. Otherpolymerization conditions such as presence of hydrogen for molecularweight control, other polymerization catalysts, etc., are applicablewith this polymerization process and may be found in the referencescited herein.

[0026] By “copolymerizable olefin” is meant an olefin which, when usingthe particular polymerization catalyst system chosen, will copolymerizewith ethylene and the acrylate ester(s) used, as well as any othercomonomers present.

[0027] The steric effect of various groupings has been quantified by aparameter called Es, see R. W. Taft, Jr., J. Am. Chem. Soc., vol. 74, p.3120-3128, and M. S. Newman, Steric Effects in Organic Chemistry, JohnWiley & Sons, New York, 1956, p. 598-603. For the purposes herein, theE_(s) values are those for o-substituted benzoates described in thesepublications. If the value for E_(s) for any particular group is notknown, it can be determined by methods described in these publications.For the purposes herein, the value of hydrogen is defined to be the sameas for methyl. By a group contained within R² having a certain E_(s) ismeant that any portion or all of R² may be arbitrarily chosen (this maybe done multiple times), and if that portion has an E_(s). of about −1.0or less, it meets this limitation. For example, if R² was2,4,4-trimethylpentyl (or in other words the ester was an ester of3,5,5-trimethylhexan-1-ol), the group —CH₂C(CH₃)₃ is found within2,4,4-trimethylpentyl, and so it would meet the limitation on E_(s).

[0028] Preferred transition metals herein are in Groups 3-11 and thelanthanides (IUPAC notation), more preferably Groups 8-11, andespecially preferably Group 10. Specific preferred transition metals areNi, Pd and Cu, and Ni is especially preferred.

[0029] Which catalysts will copolymerize what types of olefins are knownin the art, see for instance previously incorporated U.S. Pat. No.5866663 and S. D. Ittel, et al., Chem. Rev., vol. 100, p. 1169-1203(2000) (and references cited therein), as well as WO9905189, WO9909078,WO9837110, U.S. patent application Ser. No. ______ (filed concurrentlyon May 31, 2001, Applicant's reference CL1607 US NA), and U.S. patentapplication (filed concurrently on May 31, 2001, Applicant's referenceCL1655 US NA), all of which are hereby incorporated by reference for allpurposes as if fully set forth. These references also give details ofpolymerization process conditions for such polymerizations, andreference may be had thereto for further details.

[0030] Examples of preferred acrylate esters of the formulaH₂C=CHC(O)OR¹ include those wherein:

[0031] R¹ is —CH₂CH₂X, wherein X is hydrocarbyloxy or substitutedhydrocarbyloxy, preferably aryloxy and substituted aryloxy, andespecially phenoxy; or

[0032] R¹ is —CH₂CH₂X, wherein X is aryl or substituted aryl, preferablyX is phenyl; or

[0033] R¹ is n-alkyl containing 6-12 carbon atoms, more preferably R¹ isn-hexyl; or

[0034] R¹ is —CH₂R² wherein R contains a quaternary carbon atom, morepreferably R² is 2,4,4-trimethylpentyl; or

[0035] R¹ is —CH₂R² wherein R contains a group having an E_(s) of about−1.0 or less, more preferably about −1.5 or less, and especiallypreferably about −1.7 or less.

[0036] It is preferred that the copolymers described herein have thefollowing features:

[0037] they contain about 1.0 to about 10 mole percent of the acrylateester; and/or

[0038] when they are a copolymer of only ethylene and one or moreacrylate esters, they have at least 10 branches of the formula —(CH₂)CH₃, wherein z is 0, 1, 2 or 3, present in the polymer (this is measuredby ¹³C and/or ¹H NMR, see for example previously incorporated U.S. Pat.No. 5,866,663 for details of how to measure branching), and morepreferably there are more methyl than ethyl branches present in thesebranched polymers; and/or

[0039] when they are a copolymer of only ethylene and one or moreacrylate esters, they have at least 50 branches of the formula —(CH₂)CH₃, wherein z is 0, 1, 2 or 3, present in the polymers (this ismeasured by ¹³C and/or ¹H NMR, see for example previously incororatedU.S. Pat. No. 5,866,663 for details of how to measure branching).

[0040] When R¹ is —(CH₂CH₂)X or n-alkyl containing 6 or more carbonatoms, analysis of the polymer for acrylate ester homopolymer byproductis relatively easy by ¹H-NMR, since certain peaks in the NMR spectrumfor homopolymer and desired copolymer are separated, see FIG. 1 hereinwhich is a ¹H-NMR of such a mixture. When a more “commonly used”acrylate ester, such as methyl acrylate, is used, the peaks overlapgreatly making accurate analysis impossible, as shown in FIG. 2.

[0041] Besides reducing analysis costs, a quick and inexpensiveanalytical method allows changes to be made promptly in thepolymerization process, thus ensuring more consistent product and lessout of specification product to be made.

[0042] When R¹ is —CH₂R² as defined above, there is a much lowerpropensity to form acrylate ester homopolymer, an obvious advantage inmaking copolymer, since homopolymer formation is much less ornonexistent. This is illustrated in Examples 2 and 3.

[0043] The polymers of the present invention are useful as moldingresins and for films. They are also (depending on their molecular weightand physical properties) useful as:

[0044] 1. Tackifiers for low strength adhesives (U, vol. A1, p. 235-236)are a use for these polymers. Elastomeric and/or relatively lowmolecular weight polymers are preferred.

[0045] 2. The polymers are useful as base resins for hot melt adhesives(U, vol. A1, p. 233-234), pressure sensitive adhesives (U, vol. Al, p.235-236) or solvent applied adhesives. Thermoplastics are preferred forhot melt adhesives. The polymers may also be used in a carpetinstallation adhesive.

[0046] 3. Base polymer for caulking of various kinds is another use. Anelastomer is preferred. Lower molecular weight polymers are often used.

[0047] 4. The polymers, particularly elastomers, may be used formodifying asphalt, to improve the physical properties of the asphaltand/or extend the life of asphalt paving, see U.S. Pat. No. 3,980,598.

[0048] 5. Wire insulation and jacketing may be made from any of thepolymers (see EPSE, vol. 17, p. 828-842). In the case of elastomers itmay be preferable to crosslink the polymer after the insulation orjacketing is formed, for example by free radicals.

[0049] 6. The polymers, especially the branched polymers, are useful asbase resins for carpet backing, especially for automobile carpeting.

[0050] 7. The polymers may be used for extrusion or coextrusion coatingsonto plastics, metals, textiles or paper webs.

[0051] 8. The polymers may be used as a laminating adhesive for glass.

[0052] 9. The polymers are useful for blown or cast films or as sheet(see EPSE, vol. 7 p. 88-106; ECT4, vol. 11, p. 843-856; PM, p. 252 andp. 432ff). The films may be single layer or multilayer, the multilayerfilms may include other polymers, adhesives, etc. For packaging thefilms may be stretch-wrap, shrink-wrap or cling wrap. The films areuseful for many applications such as packaging foods, geomembranes andpond liners. It is preferred that these polymers have somecrystallinity.

[0053] 10. The polymers may be used to form flexible or rigid foamedobjects, such as cores for various sports items such as surf boards andliners for protective headgear. Structural foams may also be made. It ispreferred that the polymers have some crystallinity. The polymer of thefoams may be crosslinked.

[0054] 11. In powdered form the polymers may be used to coat objects byusing plasma, flame spray or fluidized bed techniques.

[0055] 12. Extruded films may be formed from these polymers, and thesefilms may be treated, for example drawn. Such extruded films are usefulfor packaging of various sorts.

[0056] 13. The polymers, especially those that are elastomeric, may beused in various types of hoses, such as automotive heater hose.

[0057] 14. The polymers may be used as reactive diluents in automotivefinishes, and for this purpose it is preferred that they have arelatively low molecular weight and/or have some crystallinity.

[0058] 15. The polymers can be converted to ionomers, which when theypossess crystallinity can be used as molding resins. Exemplary uses forthese ionomeric molding resins are golf ball covers, perfume caps,sporting goods, film packaging applications, as tougheners in otherpolymers, and (usually extruded) detonator cords.

[0059] 16. The functional groups on the polymers can be used to initiatethe polymerization of other types of monomers or to copolymerize withother types of monomers. If the polymers are elastomeric, they can actas toughening agents.

[0060] 17. The polymers can act as compatibilizing agents betweenvarious other polymers.

[0061] 18. The polymers can act as tougheners for various otherpolymers, such as thermoplastics and thermosets, particularly if theolefin/polar monomer polymers are elastomeric.

[0062] 19. The polymers may act as internal plasticizers for otherpolymers in blends. A polymer which may be plasticized is poly(vinylchloride).

[0063] 20. The polymers can serve as adhesives between other polymers.

[0064] 21. With the appropriate functional groups, the polymers mayserve as curing agents for other polymers with complimentary functionalgroups (i.e., the functional groups of the two polymers react with eachother).

[0065] 22. The polymers, especially those that are branched, are usefulas pour point depressants for fuels and oils.

[0066] 23. Lubricating oil additives as Viscosity Index Improvers formultigrade engine oil (ECT3, Vol 14, p. 495-496) are another use.Branched polymers are preferred. Ethylene copolymer with acrylates orother polar monomers will also function as Viscosity Index Improvers formultigrade engine oil with the additional advantage of providing somedispersancy.

[0067] 24. The polymers may be used for roofing membranes.

[0068] 25. The polymers may be used as additives to various moldingresins such as the so-called thermoplastic olefins to improve paintadhesion, as in automotive uses.

[0069] 26. A flexible pouch made from a single layer or multilayer film(as described above) which may be used for packaging various liquidproducts such as milk, or powder such as hot chocolate mix. The pouchmay be heat sealed. It may also have a barrier layer, such as a metalfoil layer.

[0070] 27. A wrap packaging film having differential cling is providedby a film laminate, comprising at least two layers; an outer reversewhich is a polymer (or a blend thereof) described herein, which containsa tackifier in sufficient amount to impart cling properties; and anouter obverse which has a density of at least about 0.916 g/mL which haslittle or no cling, provided that a density of the outer reverse layeris at least 0.008 g/mL less than that of the density of the outerobverse layer. It is preferred that the outer obverse layer is linearlow density polyethylene, and the polymer of the outer obverse layerhave a density of less than 0.90 g/mL. All densities are measured at 25°C.

[0071] 28. Fine denier fibers and/or multifilaments. These may be meltspun. They may be in the form of a filament bundle, a non-woven web, awoven fabric, a knitted fabric or staple fiber.

[0072] 29. A composition comprising a mixture of the polymers herein andan antifogging agent. This composition is especially useful in film orsheet form because of its antifogging properties.

[0073] 30. If the polymers are functionalized with monomers such asfluoroalkyl acrylate esters or other fluorine-containing monomers, theyare useful for selectively imparting surface activity to polyolefins.This would be of use reducing fluid penetration in flash-spun polyolefinfilms for medical and other applications. The fluoro-functionalizedpolyolefins would also be useful for dispersing fluoropolymers inlubricant applications.

[0074] 31. Mixtures of ethylene homopolymers or oligomers together withcopolymers of ethylene and acrylates and optionally other monomers areuseful as adhesion promoters, surface active agents, tougheners, andcompatibilizers for additives.

[0075] In the above use listings, sometimes a reference is given whichdiscusses such uses for polymers in general. All of these references arehereby included by reference. For the references, “U” refers to W.Gerhartz, et al., Ed., Ullmann's Encyclopedia of Industrial Chemistry,5th Ed. VCH Verlagsgesellschaft mBH, Weinheim, for which the volume andpage number are given, “ECT3” refers to the H. F. Mark, et al., Ed.,Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., John Wiley &Sons, New York, “ECT4” refers to the J. I Kroschwitz, et al., Ed.,Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., John Wiley &Sons, New York, for which the volume and page number are given, “EPSE”refers to H. F. Mark, et al., Ed., Encyclopedia of Polymer Science andEngineering, 2nd Ed., John Wiley & Sons, New York, for which volume andpage numbers are given, and “PM” refers to J. A. Brydson, ed., PlasticsMaterials, 5 Ed., Butterworth-Heinemann, Oxford, UK, 1989, and the pageis given.

[0076] In the Examples except where noted, all pressures are gaugepressures. In the Examples, the following abbreviations are used:

[0077] Am—amyl

[0078] Ar—aryl

[0079] BAF—B(3,5-C₆H₃-(CF₃)₂)₄ ⁻

[0080] BArF—B(C₆F₅)₄ ⁻

[0081] BHT—2,6-di-t-butyl-4-methylphenol

[0082] Bu—butyl

[0083] Cmpd—compound

[0084] E—ethylene

[0085] EG—end-group, refers to the ester group of the acrylate beinglocated in an unsaturated end group of the ethylene copolymer

[0086] EGPEA—2-phenoxyethyl acrylate

[0087] Eoc—end-of-chain

[0088] Equiv—equivalent

[0089] Et—ethyl

[0090] Ets-Bu(%)—percent of ethyl branches occurring in secbutyl-endedbranches

[0091] GPC—gel permeation chromatography

[0092] HA—hexyl acrylate

[0093] Hex—hexyl

[0094] IC—in-chain, refers to the ester group of the acrylate beingbound to the main-chain of the ethylene copolymer

[0095] Incorp—incorporation

[0096] i-Pr—iso-propyl

[0097] M.W.—molecular weight

[0098] MA—methyl acrylate

[0099] Me—methyl

[0100] MeOH—methanol

[0101] Mes-Bu(%)—percent of methyl branches occurring in sec-butyl-endedbranches

[0102] MI—melt index

[0103] Mn—number average molecular weight

[0104] Mp—peak average molecular weight

[0105] Mw—weight average molecular weight

[0106] Nd—not determined

[0107] PDI—polydispersity; Mw/Mn

[0108] PE—polyethylene

[0109] PEA—2-phenethyl acrylate

[0110] Ph—phenyl

[0111] Press—gauge pressure

[0112] RI—refractive index

[0113] Rt—room temperature

[0114] t-Bu—t-butyl

[0115] TCB—1,2,4-trichlorobenzene

[0116] Temp—temperature

[0117] THA—3,5,5-trimethylhexyl acrylate

[0118] TO—number of turnovers per metal center=(moles monomer consumed,as determined by the weight of the isolated polymer or oligomers)divided by (moles catalyst)

[0119] Total Me—total number of methyl groups per 1000 methylene groupsas determined by ¹H or ¹³C NMR analysis

[0120] UV—ultraviolet

[0121]¹H NMR spectra were obtained on a 500 MHz Bruker Avancespectrometer on a 5 mm QNP probe on samples diluted ˜10 mg/0.5 mL intce-d2 at 1200C using a 90 degree pulse of 14 μsec, a spectral width of12.8 kHz, an acquisition time of 2.6 sec and a recycle delay of 30 sec.A total of 8 transients were acquired. Spectra were referenced to tce-d2at

[0122]5.928 ppm. Unique peaks in each spectrum from the different typesof comonomer signals, for example from 4.25 to 4.55 ppm for theEthylene/Ethylene glycol phenyl ether acrylate copolymer, and also thePE signals in the region 0.6-2.0 ppm, were carefully integrated and theresults used to calculate mole % acrylate incorporation.

[0123] Total methyls per 1000 CH₂ are measured using different NMRresonances in ¹H and 13C NMR spectra. Because of accidental overlaps ofpeaks and different methods of correcting the calculations, the valuesmeasured by ¹H and ¹³C NMR spectroscopy will not be exactly the same,but they will be close, normally within 10-20% at low levels of acrylatecomonomer. In ¹³C NMR spectra, the total methyls per 1000 CH₂ are thesums of the 1B₁₁, 1B₂, 1B₃, and 1B₄+, EOC resonances per 1000 CH₂, wherethe CH₂'s do not include the CH₂'s in the alcohol portions of the estergroup. The total methyls measured by ¹³C NMR spectroscopy do not includethe minor amounts of methyls from the methyl vinyl ends nor the methylsin the alcohol portion of the ester group. In ¹H NMR spectra, the totalmethyls are measured from the integration of the resonances from 0.6 to1.08 ppm and the CH₂'s are determined from the integral of the regionfrom 1.08 to 2.49 ppm. It is assumed that there is 1 methine for everymethyl group, and ⅓of the methyl integral is subtracted from themethylene integral to remove the methine contribution. The methyl andmethylene integrals are also usually corrected to exclude the values ofthe methyls and methylenes in the alcohol portion of the ester group, ifthis is practical. Because of the low levels of incorporation, this isusually a minor correction. Corrections are also made to exclude anycontributions from acrylate homopolymer to the methyl or methyleneintegrals in both the ¹³C and ¹H spectra where this is warranted.

[0124] General Information Regarding Molecular Weight Analysis:

[0125] GPC molecular weights are reported versus polystyrene standards.Unless noted otherwise, GPC's were run with RI detection at a flow rateof 1 mL/min at 135° C. with a run time of 30 min. Two columns were used:AT-806MS and WA/P/N 34200. A Waters RI detector was used and the solventwas TCB with 5 grams of BHT per gallon. Dual UV/RI detection GPC was runin THF at rt using a Waters 2690 separation module with a Waters 2410 RIdetector and a Waters 2487 dual absorbance detector. Two Shodex columns,KF-806M, were used along with one guard column, KF-G.

[0126] In addition to GPC, molecular weight information was at timesdetermined by ¹H NMR spectroscopy (olefin end group analysis) and bymelt index measurements (g/10 min at 190° C.)

[0127] General Procedure A for Ethylene Polymerizations andCo-polymerizations:

[0128] In a nitrogen-filled drybox, a 40 mL glass insert was loaded withthe nickel compound and, optionally, a Lewis acid (e.g., BPh₃ orB(C₆F₅)₃) and borate (e.g., NaBAF or LiBArF), and any other specifiedcocatalysts and other additives. Next, the solvent was added to theglass insert followed by the addition of any co-solvents and thencomonomers. The insert was greased and capped. The glass insert was thenloaded in a pressure tube inside the drybox. The pressure tube was thensealed, brought outside of the dry-box, connected to the pressurereactor, placed under the desired ethylene pressure and shakenmechanically. After the stated reaction time, the ethylene pressure wasreleased and the glass insert was removed from the pressure tube. Thepolymer was precipitated by the addition of MeOH (˜20 mL). The polymerwas then collected on a frit and rinsed with MeOH and, optionally,acetone. The polymer was transferred to a pre-weighed vial and driedunder vacuum overnight. The polymer yield and characterization were thenobtained.

EXAMPLES 1-5

[0129] Examples 1-5 are listed in Tables 1 and 2 below. Figures forcompounds 1 through 4 are shown above. The polymerizations were carriedout according to General Procedure A. Varying amounts of acrylatehomopolymer are present in the isolated polymers. In Table 1, the yieldof the polymer is reported in grams and includes the yield of thedominant ethylene/acrylate copolymer as well as the yield of anyacrylate homopolymer that was formed. Molecular weights were determinedby GPC, unless indicated otherwise. Mole percent acrylate incorporationand total Me were determined by ¹H NMR spectroscopy, unless indicatedotherwise. Mole percent acrylate incorporation is typicallypredominantly IC, unless indicated otherwise. TABLE 1 E/AcrylateCopolymerizations (6.9 MPa E, 120° C., 18 h) Acrylate mL B(C₆F₅)₃Acrylate Homo- Cmpd (Solvent (Borate Yield^(a) Incorp. Total polymer^(b)g Ex (mmol) mL) equiv) g mol % M.W. Me (¹³C NMR) 1 1 EGPEA 2 20 equiv8.06 1.5 M_(p) = 3,098; 22.3 — (0.02) (p-Xylene (NaBAF 0.7 IC M_(w) =3,461; 8) 10) 0.8 EG M_(n) = 1,122; PDI = 3.09 2 2 EGPEA 2 40 equiv 2.170.03 M_(p) = 12,550; Nd 0.031 g (0.02) (TCB 8) (None) (¹³C) M_(w) =13,744; (1.43% of M _(n) = 5,936; total yield) PDI = 2.32 3^(e) 2 THA 240 equiv 2.37 0.23 M_(p) = 12,775; 43.1 Not detected (0.02) (TCB 8)(None) (¹³C) M_(w) = 13,777; (¹³C) M_(n) = 7,165; PDI = 1.92 4 3 HA 4 40equiv 2.09^(c) 4.0 M_(p) = 931; 54 — (0.02) (TCB 6) (None) 2.2 IC M_(w)= 1,399; 1.8 EG M_(n) = 856; PDI = 1.63 5^(d) 4 PEA 1 211 0.043 1.4M_(p) = 6,238; 44.4 — (0.0019) (TCB 9) equiv M_(w) = 8,319; (NaBAF M_(n)= 4,238; 105) PDI = 1.96 # (IC resonance) and homopolymers of HA andEGPEA shown in the figures herein are approximately 0.03 ppm and 0.08ppm, respectively;

[0130] TABLE 2 ¹³C NMR Branching Analysis for THA Copolymer of Example 3Total Hex+ Am+ Bu+ Me_(s-Bu) Et_(s-Bu) Me Me Et Pr Bu & eoc & eoc & eoc(%) (%) 43.1 29.0 4.4 2.1 1.7 3.8 7.5 7.6 2.3 15.1

What is claimed is:
 1. A process for the manufacture of a copolymer,comprising the step of contacting, under polymerization conditions, amonomer component comprising ethylene and one or more acrylate esters,and a polymerization catalyst system containing a transition metal,wherein said one or more acrylate esters comprises a compound of theformula H₂C=CHC(O)OR¹, wherein: R¹ is —CH₂CH₂X, an n-alkyl containing 6or more carbon atoms, or —CH₂R²; X is aryl, substituted aryl,hydrocarbyloxy, substituted hydrocarbyloxy, fluoro or fluoroalkyl; andR² is an alkyl containing at least one quaternary carbon atom, or havinga grouping within R² having an E_(s) of about −1.0 or less, or both. 2.The process of claim 1, wherein X is hydrocarbyloxy or substitutedhydrocarbyloxy.
 3. The process of claim 1, wherein X is aryloxy orsubstituted aryloxy.
 4. The process of claim 1, wherein X is phenoxy. 5.The process of claim 1, wherein X is aryl or substituted aryl.
 6. Theprocess of claim 1, wherein X is phenyl.
 7. The process of claim 1,wherein R¹ is n-alkyl containing 6 to 12 carbon atoms.
 8. The process ofclaim 7, wherein R¹ is n-hexyl.
 9. The process of claim 1, wherein R¹ is—CH₂R² and R² is 2,4,4-trimethylpentyl.
 10. The process of claim 1,wherein R¹ is —CH₂R² and R2 contains a group having an E_(s) of about−1.5 or less.
 11. The process of claim 1, wherein ethylene and one ormore acrylate esters are the only monomers present.
 12. The process ofclaim 1, wherein said transition metal is nickel, palladium or copper.13. The process of claim 1, wherein said transition metal is nickel. 14.A copolymer of ethylene, one or more acrylate esters and, optionally,one or more other copolymerizable monomers, provided that said acrylateesters are about 0.1 to about 30 mole percent of the total number of allrepeat units in said copolymer, and provided that said one or moreacrylate esters comprises a compound of the formula H₂C=CHC(O)OR¹,wherein: R¹ is —(CH₂CH₂)X, n-alkyl containing 6 or more carbon atoms, or—CH₂R²; X is aryl, substituted aryl, hydrocarbyloxy, substitutedhydrocarbyloxy, fluoro, or fluoroalkyl; and R² is alkyl containing atleast one quaternary carbon atom, or having a grouping within R² havingan E_(s) of about −1.0 or less, or both.
 15. The copolymer of claim 14,wherein X is hydrocarbyloxy or substituted hydrocarbyloxy.
 16. Thecopolymer of claim 14, wherein X is aryloxy or substituted aryloxy. 17.The copolymer of claim 14, wherein X is phenoxy.
 18. The copolymer ofclaim 14, wherein X is aryl or substituted aryl.
 19. The copolymer ofclaim 14, wherein X is phenyl.
 20. The copolymer of claim 14, wherein R¹is n-alkyl containing 6 to 12 carbon atoms.
 21. The copolymer of claim20, wherein R¹ is n-hexyl.
 22. The copolymer of claim 14, wherein R¹ is—CH₂R² and R² is 2,4,4-trimethylpentyl.
 23. The copolymer of claim 14,wherein R¹ is —CH₂R² and R² contains a group having an E_(s) of about−1.5 or less.
 24. The copolymer of claim 14, wherein ethylene and saidone or more acrylate esters are essentially the only monomers present.25. The copolymer of claim 24, wherein said copolymer has at least 10branches of the formula —(CH₂)_(z)CH₃, wherein z is 0, 1, 2 or
 3. 26.The copolymer of claim 25, wherein there are more methyl branches thanethyl branches in said copolymer.
 27. The copolymer of claim 24, whereinsaid copolymer has at least 50 branches of the formula —(CH₂) CH₃,wherein z is 0, 1, 2 or 3.